Battery and Energy Technologies

Charger Specification Checklist

The need to specify a matching charger for the chosen battery technology can not be over emphasised. As pointed out in the section about Chargers the use of an inappropriate charging method can seriously shorten the life of a battery or even kill it outright. A well designed "Intelligent Charging System" however can extend the life of the battery.

As with batteries, most of the information needed to specify a charger for a particular application is listed on the "Charger Quotation" page and in the main this should be self explanatory. Some further explanation is however given below.

In specifying chargers there are some factors which are mandatory and some which are optional.

Essentials

The most important requirement of a charger is that it should be appropriate for the cell chemistry of the chosen battery since the use of unsuitable chargers can damage the battery. The section on Chargers describes some of the many options available.

There should be some method of protecting against overcharging. The specification should indicate whether this is to be incorporated in either the battery or the charger.

The charger design should also match the intended use profile of the battery. Will it be off line charging only? Is trickle charging required? Is float charging required?

The desired charging time must be specified.

The capacity of the charger should be sufficient to charge the battery within the desired time.

The power source must be specified. This could be the AC mains, DC battery power, opportunity (variable) charging from vehicle, solar or wind sources or a combination of these.

For high power applications the charger performance (efficiency, inrush current handling, power factor) becomes significant.

Options

There will be trade offs to be made in the design of the actual charger usually between efficiency and cost. Different types of voltage regulators such as "switch mode" , "linear" or "buck" may be used.

The charger may be integrated with the battery electronics to form an Intelligent Charging System. Although complex, such a system can significantly prolong the battery life.

The charger may also incorporate a data logging facility, to identify individual batteries and store key data about their history.

There is always the possibility to add lights to indicate the progress of the charge and or warning lights.